US Patent 7612590 Oscillating apparatus

An oscillating apparatus is provided that includes: an integration circuit that outputs a control signal based on an integration value of two inputted voltage values; an oscillator that outputs an oscillation signal of a frequency that is based on the control signal; a phase comparator that outputs a phase difference signal of a pulse width that is in accordance with a phase difference between the oscillation signal and the reference signal, by comparing the oscillation signal with a reference signal of a predetermined frequency; a controlling circuits that controls the two inputted voltage values based on the phase difference signal, so as to approximate a phase difference between the oscillation signal and the reference signal to a predetermined reference phase difference; and a voltage stabilizing current that defines the two inputted voltages based on a predetermined reference voltage.